Hello everyone,
unfortunately, my external battery has only ~80% of its capacity. Other people have the same problem, that a soldering point between the cells is broken.
In the Sony support forum, one user was able to open the battery, but I'm scared to damage a cell. (see https://community.sony.com/t5/VAIO-Hardware-Networking/Vaio-pro-13-SVP13215PXB-sheet-battery-VGPBPSE38-won-t-fully/m-p/602212)
Can someone please explain me (maybe with pictures, where to pry open), how to open the sheet battery?